This invention relates to apparatus for and a method of sorting articles into a selected one of a multiplicity of receptacles. More particularly, this invention relates to apparatus for sorting packages, mail, or other articles into bags or other containers for delivery to specified locations.
Heretofore, sorting apparatus was known which sorted articles into receptacles. Such apparatus typically included a conveyor moveable along a path having a multiplicity of trays or carriers for holding one of the articles to be sorted as the conveyor moved along its path. A loader was provided to load the articles onto the trays, usually one article to a tray. A number of receptacles were located along the path of the conveyor and means was provided for dumping or otherwise unloading an article from its tray as the tray is moved along the conveyor path so as to deliver the article to a specified receptacle. Reference may be made to such U.S. Pat. Nos. as 4,567,988 and 4,688,678, and 4,895,242, and to Dutch patent 18,951 which illustrate prior art sorting machines in the same general field as the present invention.
However, as a general goal with such sorting equipment, it is highly desirable to make the sorter as "dense" as possible. That is, that the sorter have as many article receiving receptacles as possible in as small a space as possible. It is also desirable that the sorter have as high a throughput as possible thereby to enable it to sort as many articles as possible in a given time.
Toward that end, many of the prior art sorters have been designed to have multiple receptacles at each unloading station along the path of the conveyor so that at each unloading station, the article carried by a tray or carrier on the conveyor may be selectively unloaded into any one of the receptacles at any one of the unloading stations. However, this required the provision of means at each of the unloading stations responsive to a control system for effecting the release of the article from the carrier in a predetermined manner so as to direct the article into the selected one of the receptacles at that one unloading station. As shown in the co-assigned U.S. Pat. No. 4,895,242, each of the carriers was provided with a plurality of latches and cams for controlling the position of spring loaded gates on the carrier. With these gates in a first or closed position, the article was held within the carrier, with the gates in a second position the article was permitted to fall into a first receptacle, with the gates in a third position the article was permitted to fall into a second receptacle, and with the gates in a fourth position the article was permitted to fall into a third receptacle. However, the requirement of the complicated gates on each carrier, and the requirement of cams and cam actuating means at each of the unloading for stations selectively operating the gates increased the complexity and cost of this prior art sorter.
Other sorters are known, such as is shown in the co-assigned U.S. Pat. No. 4,688,678 to Zue, which utilizes horizontal carriers onto which articles are loaded. The carriers are conveyed along a path to a selected unloading station at which the article is unloaded. Each unloading station is provided with a drop chute having a plurality of diverter gates which direct an article falling downwardly within the chute into a predetermined one of the receptacles at that unloading station.
U.S. Pat. No. 4,567,988 discloses sorting apparatus in which an article to be sorted is loaded onto a carrier and the carrier is conveyed along a path to a specified unloading station. Each of the carriers is provided with a bottom release gate which when opened releases the article to fall downwardly. Along the conveyor path, chutes are provided into which the articles are dropped such that the chutes direct the article into a selected one of the receptacles.
Dutch Patent 18,951 discloses sorting apparatus in which each of the carriers is mounted on the conveyor in such manner as to be tilted to an inclined position thereby to direct the package carried thereby to be directed into a specified chute to be delivered into a selected receptacle. However, this Dutch sorter requires a complicated mechanism for moving the carrier to its desired tilted position.